Telephone exchange system



Oct. 2, -1945. G. DEAKIN .TELEPHONE EXCHANGE sYsTEM 5 Sheets-Sheet 1 Filed 'June 7, 1943 l Awb-DOM: U

- INVENTOR 65E/4L@ DFKY.

BY /f l Y AGEN:

` Oct. 2, 1945. v G. DEAKIN TELEPHONE EXCHANGE SYSTEM Filed June l'7,v 194s AGENT O'cf. 2, 1945. G. DEAKIN TELEPHONE EXCHANGE SYSTEM Filed June 7, 1943 A5 Sheets-Sheet 3 ..5 MERE@ mz3 Sow 5 Smets-sheet 4 5385@ Si r Oct. 2, 1945.- cs. DEAKIN i TELEPHONE EXCHANGE SYSTEM Filed .June 7, 194s Oct. 21945.

G. DEAKIN vTELEPHONE EXCHANGE SYSTEM Filed June '7,'1943 5 Sheets-Sheet 5 AGENT Patented Oct. 2, 1945 UNITED STATES PATENT OFFICE TELEPHONE EXCHANGE SYSTEM Gerald Deakin, New York, N. Y., assignor to International Standard Electric Corporation, New York, N. Y., a. corporationof Delaware Application June 7, 1943, Serial No. 489,883

43 Claims.

the central exchange and later repeated to theV subscriber, or any other similar service or combination of services may be accomplished by means provided at the central exchange without permanently tying up any of the switching devices used for the customary establishment of connections between calling and called subscribers.

In accordance with the present invention, this is accomplished by providing a plurality of special line service circuitsY at the exchange. Any one of these may be taken into use by a subscriber entitled to this special service, whereupon thev circuit taken into use will be attached to such subscribers line by means separate from the customary switching devices of the exchange, e. g. a special relay or set of relays. All connections established to this subscribers line will thereafter be handled by the equipment provided in the special service circuit taken into use. Upon his return, the subscriber may communicate with such circuit and obtain the information required.

The arrangement herein disclosed may be utilized also for providing a subscriber with superaudio tele-program service, to provide private connections with a toll board, a telegraph oflice or stock ticker, for providing special'night service for P. B. X.s, and Afor many other purposes'too numerous to mention.

The present invention may be embodiedjin any suitable telephone exchange system. As here illustrated, it is particularly adapted to cooperate with the system Ldisclosed in my co-pending application, Serial No. 484,184, led April 23, 1943.

The invention will now be described with reference to the drawings inwhich:

Fig.A 1 is a general block diagram of the system; s

Fig. 2- diagrammatically illustrates'the special line service selection circuits and as much of the central exchange switching equipment as is necessary for an understanding of the present invention;

Fig. 3 is a diagram illustrating an attendants position which may be provided at a special line service circuit to take care of calls that come in during the absence of a subscriber; and

Figs. 4 and 5 (one being placed above the other) diagrammatically illustrate a special line service circuit provided with a phonographic recording and reproducing means to record messages received during the absence of asubscriber and later to play them back to the subscriber under his control.

Special tele-program service selection As shown in Fig. 1 the special line service circuits are jumpered to the subscribers line at the main distributing frame M. D. F. and no alteration whatsoever is made in the regular switching circuits. It is possible, if ever necessary, to jumper as many `as ten different special line services to the same line. A typical case of jumpering is shown in Fig. 2.

In Fig. 1 is diagrammatically shown the usual arrangement of rst and second line finders, intermediate group selectors and nal selectors. It is assumed that the 0 level of the first group selectors will be reserved for trunks to special service second group selectors. It is further assumed thatthe 00 level of the special service second group selectors will be reserved for trunks to a small group of special line service third group selectors, the ten levels of which are connected respectively to the ten special line service selection circuits and, therefore,l have the numbers 001 to 000. Two or three thord group selectors would serve a 10,000 line oice. All of the special line service circuits responding to the same number are connected by a common lead to the corresponding special service selection circuit. The amount of vcommon equipment for a 10,000 line office is very small.

When a subscriber has dialed a three digit special line service number, the corresponding special line service circuit is connected for use within a second and the special line service selection circuit instantly freed thereafter, providing that the identification circuit (Fig. 2) is not in use by the wire chief or by a toll operator. If it is so used, then the special line service call must wait for two to four seconds, after which the special line service circuit is connected and the selection circuit' freed in a second or less. Two or three special line service third group selector circuits are provided so that subscribers may not lose time in picking up a selector on account of slow dialing on the part of a subscriber or on account of many simultaneous calls,l but only one special line service selection circuit may be in use at the same time.

selects the 0 levelot theffirst groupselector, the l second digit the 00 level of the special service second group selector",` and the third digit the Wanted level -dffthe special une service wird groupslector which we will assume in'this case is 001. lector functions during selection in the same manner as any other group selector. The'operation; of the added relay ER in the 3rd GS will be describer hereinafter, f

When the brushes of thethird group Yselector come to rest ,0D the terminals of, the special line service selection circuit, Athecircuit ofthe b Wire will be grounded over resistance Rl This releases tfleiegister as -cna shortA number call.

. chief be "using the identification circuit, relay' GRV When the() brush Q fthe,special4 service third group selector makes Contact with the C Vterminal, it operates relay SCR of the special line service selection circuit, in this case." circuit No. 001'.. Each of these circuits has only this one relay. Relays SBR and STRl are common to all tensel'ectin circuits.' RelaySGR `energ'izes relay STR Wl'iichremoves'v the test potentials'frm the T terminals of all ten levels, thus makingit impossible forranotherspecial service thirdg'roup selector vto pick up 'asecondA special line service selection circuit. Y -Y 'K Should the common identification `Vcircuit be in use'by a toll operator, relay ARI of the identification link will be energized.vvv Should the local wire will be energized. 'When eitherof these relays islenergi'zed, ground-is removed from relay SBR: Eoweverjwnen the identification vlink is not'being usedb'y eithera tolly operatorl or the'wire chief, a circuit "is"established@from.r ground, back ARI, haciaV CR, 'winding SBR, iront SCR to battery.

. SBR 'operates anuvre'moves ground from A Rl -an-d CR of identicatin link,thus makingl thel iden--V ti-ic'ationV circuit vbusy to operator. Y Q

vRelalySBR `also removes battery from the windings 'of ARE! of all r'st'identiflatioh ylnclerciicuitsof which vvthere would' be one hundred in'a 10,900 vline oice. `V`Over a front contact -SBR places positive battery overV the front contact of SCR on the t Wire, thus energizing the identication'relay IR of the A-li'nk. /AR2 of the iirst identification 4'inder'does not Voperate "since, gas before stated, its"cir cuit is nowopen, thus the associ-atedidenticationnder does not hunt. IR places 'a predetermined battery potential on the't wire ofthe calling subscribens line vand a circuit .is closedfrom'ground, front SBR,frontv SCR, common lead `toall special line serviceV circuits No. 001, Winding SSR1 jumpered tocalling line,"twire`oi3calling subscribersline, Tbrush o fprst line nder, front IR,to positive battery. SSR-ifoperates and locks upover a front lContact in` series` withthe back contact of DR., This special ,linev service circuitrcannot now be released., until, DR is energized i f Finallyy SBR. QlQSese. circuit. from ground, front the wire chiefand toil Ait The special line service thirdv groupse-k vreleases the finders and selectors. energizaticnSCR releases relays STR and SBR,

' a "busy tonev circuit over the "a and b wires and thecallin'g subscriber hears 'the busty tone (sometimes nct needed), whereupon he hangs up and Upon its dethereby restoring vthe special line service selection 'circuits Yaind-'theidentification circuits to normal.

'beforetatedgthe special line service circuit No. 1, i.-`e. relaySSRi, remains locked up over the yback `contact of DR.

he central oiice'the special 4line'service circuit, consisting .of seven relays is.V junipered 2li..i1ie fmefi1 @istribiiiing treme Yim@ the Sube. Scrivere.. 1in@ es. Shewn ie. Fis "3- 'NQ lchenee. is.

I required nfthel elitemeiligequirment indicated in the, weer par@ 0f` Fie 2- The Spcial, line Service circuit is/connected bylavtwo-wire trunk toa manual 'attendants positionuin the same o1-Qa` distance oi'ce whereY i1; terminates in two ad- Qliti9ne1,;re1ays., line relay `SLR and a, `@11i-off relay VCOR an answering jack AJ, and a line lamp Il@ aitendenisiwsition is equipped.: with@ few Cordireuits each ,havin-g a listening. key and a ring-back key RK. Y

Absenteefliie circuit connected for 'service when ynot "connected "for service, 'the absentee line rlcuitl'ernains' inactive-,n calls to and from tliel'fsubscriber. Relay. 3DR 'isfdiffernt'ially wound` and does 'not'op'erate., Also, because kof this diiierential winding., it' ciie'rslittle iridafnce to speech tfansmissionbi if further. 'reduction' in 'impedance is 'rec`1uire`d',l the two windings. 'may be shura-ited' by suitablecondensers or noninductive esistan'csfthe'latter "being .'fnuh jthe cheaper. f

Top'ut th`e absentee v(':i'rr'z'uit into service, y'the subscriber dials theV proper three-'digit special line service number, for example, No. 001, and` inthis wayoperates relay 'SSSR as "described with reference to Fig. 2. 3SSR'locks`up vrt'he b'ak 'contact OSDR andfcuts the 'subscriberlsline in two, v"'ccnnect'ing tleoits'ijde line,"w'ires"tothe windings 'of :and the 'a` a dfb wires from the automatic switches at Athe 'central exchange "to front c'c'ritactsv of relay 'SGR isA energized over the wire cifwhenthesubscribers cutif relay vCQR (see zF"1g`2`)V pratesfand opens' the operating circuitY ofAR. When 'SSSR Vo'p'erisgthe.

operating `SLR which locks up and lights line lamp LL. Upon the closure of the top front contact of SAR, 3BR is short-circuited andcloses the trunk circuit from the attendant through to the calling subscriber over front contacts of SAR. SAR disconnects SFR and SER and removes battery from SGR. The subscriber is thus enabled to Vtalkvwith the attendant when the latter answers. The calling subscriber does not receive a busy tone to indicate completion of a special line service connection. When the subscriber hangs up, SAR is' released, but SSSR remains locked up. At the operators position SCOR and SLR release when the attendant removes the cord from the jack AJ.

Absentee sabscribers line called by distant station When a distant station operates a nal selector to seize the absentee subscribers line, COR of the' absentee subscribers regular line circuit operates and energiZesSGR (Fig. 3), after which ringing current passes over the a and b wires, front contacts of SSSR, front contacts of SGR, back contacts of SBR, thence to winding of SLR through condenser C3. SLR locks vup and lights line lamp LL. The attendant answers by plug; ging in her cord circuit and the center grounded repeating coil or other similar device trips the ringing relay associated with the automatic switchboard and places the calling subscriber and attendant in direct communication. The calling subscribers meter operates. The attendant takes such note of the call as may be prescribed, after which the distant calling subscriber hangs up and releases the automatic connection, but SSSR remains locked up.

Returning absentee subscriber calls attendant When the absentee subscriber returns, he removes handset, whereupon SAR and SBR operate, provided that the line is free at the central ollice and, therefore, SGR is not operated. 3BR applies a momentary impulse of ringing current to the trunk and rings up SLR which lights line lamp LL. SAR short-circuits 3BR which releases and closes the calling subscribers line through to the attendants trunk over back contacts of SBR, SGR and SER, and front contacts of SAR and SSSR. The attendant answers with cord circuit. The windings of the repeating coil shunt the windings of SAR .but not sufficiently to cause SAR to release or to apply undue current to the calling subscribers transmitter. `The attendant gives the returning absentee subscriber any messages which may have been left for him, after which the subscriber hangs up and releases SAR which restores the absentee line circuit at the central oilice to normal. SSSR does not release.

The a and b line wires fromthe automatic switchboard are connected to the attendants trunk through small capacity condensers CI and C2, the purpose of which is to enable they calling subscriber to hear that he is. being rung even while he is talking to the attendant. AHe may continue talking to the attendant since the Volume of the ringing current will not interfere with the conversation which cannot be overheard by the distant calling subscriber, or he may momentarily depress GK and release SSSR, thus connecting his line through to the automatic switchboard and to the calling subscriber.

Attendant rings absentee line Theattendant may ring back on the absentee subscribersline in the following manner. When a cord circuit is inserted into the answering jack of theA absentee line circuit, relay SFR operates over the b wire to battery at RKl in the cord circuit. SFR removes battery from 3ER and short-circuits SBR. To apply ringing current to the absentee line, the attendant depresses the cord circuit ring-back key RK, thus releasing SFR lwhich closes the circuit of SER from ground Vat the repeating coil of the cord circuit, a wire= back SBR, back SGR, back SAR, winding SER, back SFR to battery. SER applies ringing currentv to the absentee line as long as yRK is de-y pressed. When RK is released, SFR again operates, opens the circuit of SER, and again shortcircuits SBR. When the absentee subscriber answers, SAR operates, but not 3BR, thus a ringing impulse is not applied to the attendants trunk. SAR completes the talkin'g circuit over its front contacts and at the same time disconnects ySER and SFR.

Release of special line service circuit The calling subscriber may release the special line service circuit at any time, during a call, or even without removing the handset, merely by momentarily depressing GK which grounds the b 'wire and unbalances SDR, causing it to operate and open its back contact, and consequently, the holding circuit of SSSR.

The arrangementshown in Fig. 3 provides a direct line for each subscriber from his central oftice to the attendant. There may be many cases in which the central oflice will be a long way from the central oflice tovwhich the attendant is connected. In such cases it may be desirable to use a few common trunks tothe attendant from a group of subscribers and to associate these trunks with a simple identification system. The.

Absentee special Zine service with automatic recorder at central oce (Figs. 4 and 5) 5) common to a group of the individual equipments.

The individual part, the special line service circuit is jumpered into the subscribers line at the main distributing frame. The a and b connections are made on the regular terminals provided for each` line. made over jumper cables as shown on the subscribers line circuit (Fig. 1). Since but a fraction of the total lines in any office will be equipped for special line service, these jumper cables would The c1 and t connections are bemin only as .required and they would terminate at fone Y'endfon 'extra Vterminal vstrips-'on thelM. 2D. Exand at-the other endio'n extrafterminaltstrips in the line L'nder bays. The connection Lat'the bay end .wouldlbe completed by 'jumper wirertoa conveniently iexposed SI 'terminal at the :rear :of the ribbon cable and .to an exposed Yterminal at the` :rear of .the `cut-loft relay. The `individual equipment 'consists'.of ten' relays, some nfiiscellaneous apparatus and a I'recorder.

'The Lcontrolcircuit (Fig. 55) Yconsists .of'vone standard eight-brush riinder, eighteen relays and anamplier fortransmitting and .receivingto .and fromlthe recorder. 'The 'controlcircuit finder :has capacity for sixty Yspecial line service .cireuits GFi-g. 4f); lSuiicient-controlcircuits are supplied to handle the calculated 4maximum simultaneous trafiic 4on-a reasonable probability basis. .1Common to all the control circuits 'in "the `same .oce islalphonograph-and'amplier associated with an interruptor P. Int. These are"shownatthe-fbot-y tom Qi'Esf 5 Recorder Inflthe vwire recorderdiagrammatically shown in Fig. 4, there are two spoolsof Wire, a normal storage spool DI and atake-up spool D2. These two spools 'with the-other ypar-ts ofthe recorder are mounted'as aluniton a common framework answers reversed, '.RB remains iin its advanced r`position until the rriction -clutch c1. V3 is energized, "whereupon it Lreturns Ito fits Vlnormal position .under the tension Lofrectractile spring RS.

therilength of conversation which can fbe vrecorded :depends upon the .length of .the vwire on the. spools. .A standard machine has enough Wire forfaboutone hours conversation. The `speed of rewind Yis threeV times fthat 'of unwind, thus 'a fullhours conversationniay lbe rewoundin twenty minutes. This means that the Aabsentee sub scriber @must wait twenty minutes after his ireturn before fmay listen to the first recorded message inthosecases where vspool DI hasbeen fully unwound. In actual practice it assumed that 4the lan/'erfagetotal lengthA of al1 recorded-messages will be much less kthan one hourand in any case a rewound ring is given when the rewind is fcomplete.

Method .of Opera'tz'onAbsentee `Zine circuit connected for recording.

the siibscriber. To connectthespeciallineservice circuit for recording, the `subscriber Ldial's the proper three digit special line'service 'number for recording, which V-we will assume is :002, and

and ainumberof units are mounted on thesame bayone-above the otherrand driven from a common shaft.

Clutch 'magnet c1. r2, when energized, causes D2 tofrotateinthe vdirectionlofithe arrow and unwind DI.. Likewise clutch magnet cl. I causes fspool-lDtorotate in vtherdireotio'n ofthe .arrow andfunwind D2. 'When DI isfully wound, home contact assembly HCI Nis in lth'eposition lshown. Whenlclutchrcl. 2 is energized and spool .DI commencesftolunwind;contacts C4 andy-Cl make, immediatelythereafter C3 breaks, and two seconds latercontact CZYbreaks. Similarly, ron the rewind Ajust aboutas DI is fully `r'ewound, VContact', C2 makesvtwo seconds later C3 makes-.and immediatelythereaf-ter'CL and C-'break. When DI is iiill-ywwound, lD2 is obviously fullyunwound .and home contact assembly HG2 is in the position shown. L.WhenDZ is fully wound, -I-ICZ opens itsV Vscrew"L 'S`which controls the movement of brush carriage R-A. vvThe distance RA moves along'the lead screw to the right is in proportion to the length' of `wire woundon D2. 'The brush carriage RA-carriesa light;y Contact springSj and -a heavy back stop BS. RA advancesj-BSbreaks 'contact S2, SI v-i-s forced into contact Iwith `BS and lIBS slides RB alongA rod RR. YRB remains in-its advanced'positi'on `due to the friction with which its'lutch C153 A"normally grips "RR. R-B-a'dvances to?'apositionecorrespondingtothe Imost advanced positionfofiHA. j'When the A'motion Lof- RA "is in this way oilverates ivSSlnl as 'describedffwith referenceitofFigs. 1:-and.2. 4SSR1 locks up'over contacts of #IDR iand BBR -and disconnects the a andv bl =wires-ofthev subscribers `line from the *centrali oce lineair-cuit andin place thereof connects rthem to the wind-ings 'of relays vICR and 4DR. ldCRoperatesfbut'not '4DR `which -is differentially wound. HCR "closesl the f'bus'y tone circuit if the recorder yis-fully lrewoun'd,circuit from ground at HCI,` contact C3, front ASSE one winding of transformer TTI front 4CR, busy tonerl interrupter BTI :to battery. The "busy tone indicates 'to'the subscriber that the special line service circuit :isconnected forrecording The subscriber hangs up and 'releases 4CR but 4SS'R1 remains lockedup oyenthe back contact 'of 4DR.'

"The 4recorder ynormally rewinds'wh'en`the special' line 'service vcircuit `i's disconnected. 'This VVrewind 'circuit may be traced from ground "at HCI Contact C4v which isjclosed whenDl 'i'sn'ot 'fully rewound, 'clutch cl. "l, 'rectifier `S(-) back 4GB, back 4FR, .bac.k "4BR to battery. When `D| `is fullyrewound, contact'C4 opens 'andthe recorder comes "to rest. Should Lthe subscriber .reconnect the specialline service circuitbeforethe recorder isfflllly"r.eWo.un d,.` he will not hear'the'busy *tone until the rewind is complete, since .the .circuit 'of thefprimary winding. o'f the busy' tone. coil will 'be open.. at V.oo ,ritact "C3" until the rewind is complete.

-The subscriber may wait at his telephone or'he Vmay hang 11p-and check later`by again removing dER .operates an'dlocks up. It may vnot Ybe 17e-- leasednntil ASSRl isnreleased. -A calling subscriber. may not .f pick .up the recorder .while 'dFR is .deenergizedlbecause'the .circuit .of Wire `C|, extends over a frontcontac't'of vdFR.

Absentee subscribers line called When a distant station calls the absentee subs'ci'riber-slV line -over the f customary Vlintermediate and test relay TIR of the first to reach that cir-V Y cuit operates and makes the selected circuit busy over its low resistance winding in series with low resistance relay TZR. TIR opens the circuit of the power magnet and the finder comes to rest. Resistance R4 and ACSR are shunted to battery by the low resistance windings of TIR and TZR. The reduction in current is sufficient to cause ACSR to fall away and release the idle hunting iinders. dCSR, however, may be again operated by another calling special line service circuit over that circuits pair of resistances R3 and R4L Calling subscriber hears announcement The ringing current applied tothe a and b wires passes over front contacts of 4SSR1 to brushes A and B, front contacts of TZR, condensers CI and C2, winding of CLR. CLR operates and locks up over a front contact in series with a back Contact of CKR and a front contact of T2R. CLR energizes CJR when theV grounded segment of P. Int. makes Contact with brush U which is connected to a back contact of CJR. CJR locks up over a front contact in series with front contacts of CLR and TER. In the interval between the traveling of the grounded segment from brush U to brush L. a phonograph is put into operation'and connected to the a and b Wires, that is, to the calling subscribers line. A high impedance, low resistance retardation coil Ret. bridged across the a and b wires of the ampliiier associated with the phonograph trips the ringing relay and the calling subscribers meter operates. Shortly after this, the phonograph sends out on the calling line an announcement like the -r following: Party you called is absent-Your spoken message will be automatically recorded- Speak clearly and hang up promptly when finished-Go ahead now. After this announcement, brush L of P. Int. becomes grounded, thereby operating CKR which locks up over a front contact in series with a front contact of TZR and disconnects P. Int. CKR releases CLR which, in turn, releases CJR which disconnects the phonograph. Should the subscriber hang up before the full announcement has been heard, CLR is released when T2R releases. I

M essaye recorded CKR connects the amplifier circuit to the aand b wires of the calling line. The circuit maybe traced from brush A, front TZR, condenser CI,

`iront CKR, back CMR, one winding of transformer TTZ, back CMR, front CKR, condenser C2, front TZR to brush B. CKR places high tension battery HTB on the anode plate of tube V through winding of relay VOR. CKR puts the recorder into operation by energization clutch cl. 2 (Fig. l4), circuit from negative battery, front CKR, back CTR, brush E, thence in multiple through cl. 2 and rectifier S(-), windin:r of wipe-out needle W, resistance R, contact HG2 to ground. The energization of clutch cl. 2 causes the wire to move from spool DI to spool D2 and any message which may be on the wire is wiped out as it passes needle W. In this way a new Vmessage may not be recorded upon an existing message.

`The grid of V has a normal negative bias. However, `Ywhen speech currents pass through TT2, VV amplies these currents through one winding of transformer TTI, the ,second winding of which is connectedover back contacts of CMR, front contacts ofjl2R,` and brushes F and G to the winding of the combination recording and transmitting needle RT (Fig. 4) of the recorder, and Vas the magnetic wire advances, the speech currents are recorded upon it. The plate current during speech is sufficient to operate VOR, thus the circuit of a time alarm TA, which commences to move towards its ten second contact when CKR operates, is opened at the back contact 4of VOR, restoring it to its O position. Duringv intervals of Vno speech, VOR falls away and should this interval exist for ten seconds,

TA wil1 operate CTR Awhich opens the circuit of clutch cl.r2,thus causing the recorder to come to rest until speech starts again. when spool D2 is fully wound, the circuit of clutch cl. 2 is opened at HG2 and guard lamp GL burns.

Calling subscriber rleleas-es When a calling subscriber has finished dictating his message or when he otherwise hangs up,

the automatic connection is released and when does not rewind. e

' Abslentee subscriber returns 'Ihelsubscrib'er removes handset. If no message Vhas been recorded during his absence, he again 'hears the busy tone. If a message has been recorded, the busy tone will not be heard. Inleithercase, the subscriber momentarily depresses LK whichoperates 4DR, thus releasing 4SSR1 and 4FR. The subscriber replaces handset and waits for the recorder to rewind if messages are indicated. When the rewind is complete, the subscriber receives one short ring of two seconds due to the operation of relay 4RR. The circuit of this relayis momentarily closed from ground at HCI, contact CI, back 4CR, contact'CZ, winding ARR to battery. As above described, circuit to ground at HCI is closed -for two seconds only. By this means, `the subscriber is not forced to guess at the time he should wait for the rewind but is informed immediately when the rewind is complete. Should theV subscriber be talking on the line when the rewind is iinished, this short ring will not be given since the circuit of RR will be found open at 4CR which is energized by the ground on wire c1 whenever the cut-ofi Yrelay COR of the line is energized.

Absentee subscriber connects recorder jor listening still rewinding. A control circuit. picks. upV the callingspecial line serviee'circuit.. When brush C makes contact, CAR (Fig..-). and 4BR, operate in series, circuit frombattery, frontA 4`SSR2, winding 4BR, brush C, ,windingv CAR, back CBR to ground. 4BR locksup overY its front contact, and overv a back contact releasesv IlfSSRiV and dSSRz, but grounds T before IISSR?. falls off. Over anotherv back contact, 4BR removes battery from the rewind circuit ofv clutch. cl. I. 4BR disconnects the a and. b: wires of. the subscribers line fromy the automatic equipment. and'. in place thereof Vconnects them to the A andB brushes through. the twin windings. of. 4ER which have non-inductive Vshunts to permit the passage of voice currents from the recorder.. Frombrushes A and. B the circuit vcontinues over front contacts of. CAR (Fig. 5) to positive. and. negative batteryv through CDR, and CER respectively. CER and CDR operate and. CER energizesCBR. CBR removes ground fromwinding of CAR but not before it' is connected over the front contacts of CDR and CER in multipleandlin series with a front contact-ofCAR.

Should the subscriber be in doubt as to the condition of rewind, hemay find" out at any time it it isV complete, by `momentarily depressing RWK,. thereby releasing.. CER.. This will. energize CFRl', circuit. from. battery, frontT2R, back CER,.front.CDR, backCI-IRi, back'CGRi, wind'- ing CFRi. to ground.. CFR1 closes its.- front. contact andY when RWK is released,v CER is. again energized, thereby removing, the'v short-circuit from CGR1 which now operatesand locks up in series with CFR1. CGR1 connects negative bat'- tery to brush D throughr relay CNR. Should the rewind be incomplete, contact C4'.- and HCI (Fig. 4) will be closed and CNRwill operate in series with CI, rectifier SI and back 4GR. CNR connects the'y rewind tone-interr-upter'RWI to one winding. of. transformer. TTS' (Fig, 5)., the'other winding of whichis connectedacrossY thefa and b Wires through: condenser G9. The'rewinding tone is heard by the'calling subscriber who may Wait untiLthe rewind is. complete. sincev cl.Y I is now also energized, or heH may hang up and call later whenfhev hears thev rewind ring as pre--V viouslyv described. Should the rewindbe complete whenv RWK is depressed, CNR will. find an open circuit and` thesubscriber willf not hear the rewind tone.

Absentee subscriber listens to messages With the rewind complete, they subscriber depresses LK for an instant,. thereby deenergizing CRD (Fig. 5') but not. CER. CFR2 operates and after LK is releasecLCGRz operates and:- positive battery is placed on` brushD. Current. from.y this battery passes through rectiiier S(+) (Fig. 4): and' operates 4GR. EGR. connects the positive current over a front contact and energizes'clutch c1. 2. D2" commences` to unwind DI and draws the wire with the. magnetically recordedmess'ages over recording and transmitting needleRT. It will be noted that no current flows through the wipe-out magnet W since the rectifier S(-) prevents the flow' of current from the positive battery.

CBR. (Fig..5) energizesCMR. and CMR reverses the connections of the amplier transformers TTI and TTZ so-that the minute currentspicked up by needle RT are amplified.v by V and transmit'-y ted through transformer TTI. and condensers CIy and C2 to the a. and bwires, thence throughthe non-inductivewindings of 4ERto the calling-line to be heardV by the. listening., subscriber.` 'lheV subscriber may. stop repetition.. at any. time bya second momentary. depressionof LK which operates CGRZ which, in. turn, releases CFRz and CGRz.. CHRz remains energized until LK is restored. The subscriber may restart therrecorder by. a. third depression. of LK and again stop it by a fourth depression. The subscriber may rewind the message wire on spool DI as much and as many times as he desires by a similar use yof RWK. During rewinding- CNR,.(Fig. 5) isener.- gized and the subscriber hears the rewinding tone.

FromV the above it will be seen that the subscriber may have part or all of the messages repeated as many times as he wishes and that the messages remain on the'wire until the recorder is again connected for receiving. After so connected the old messages will be wiped messages are recorded.

Subscriber releases When spool D2 has wound up all recorded messages, RA comes into contact with RB in its ad-v vanced position which, as Vbefore stated, isthat position in which the last recorded message finished. Contact is made between spring SI and BS thereby closing the primary circuit of the busy tone interrupter and transformer TT2. The subscriber hears the busy tonev and unless he wishesto re-listen to all or a portion of the me-ssages, he hangs up and in so doing opens the line circuit and releases CDR and CER which opens the holding circuit of CAR and 4BR. Both circuits return to their normal disconnected condition and DI rewinds, circuit fromground at HCI, contact C4, magnet cl. I, rectier S(),. back 4GR, back IIFR, back 4BR to battery. When DI is fully rewound, C4 opens and thev recorder comes to rest. RA closes contact` S2 (opened when RA is oif-normall' and energizes clutch magnet CL3 over the latters homeV contact HCS. RB is releasedland returns toits normal position under the tension of retractile spring RS and openshome contact HCB. f

Subscriber cuts out. temporarily:

Should" the subscriber wish to cutout temporarily, he depresses AK while listeningN to a recorded message, that is, while D2 is rotating, after which he hangs up. The recorder ceases rotation and remains in its advanced positionbut the line circuit is freed to make and receive calls. When AK is depressed, IER releases and locksup 4GR, circuit from ground, one winding of 4GR, front 4GB., back 4ER to battery. When thel handset is replaced, CD15.l and CER fall away and release Ythe circuits of Figs. 4 and 5. 4GB. remains locked up until the special service line circuit is again connected .for listening, Clutch cl'. 2 falls away when TZR opens the circuit of the D brush.

Subscriber answers incoming call should the subscriber desire to answer the call without releasing.r the special line service circuit (Fig- 4)r and the control circuit (Fig. 5), he may do. so by momentarily depressing thev answering key AK which introduces resistance RI: into..the

'out as new line circuit. IER falls oil and closesv a circuit from ground at the energized cut-off relay of the subscribers line circuit,-Wire c1, front 4BR, back AER, winding, 4AR to battery. AAR can be operated only when there is a ground on wire ci and locks up over a front contact arid a front of 4BR to this ground. The ringing current is tripped by a circuit which may be traced from the a wire, resistance R2, front 4AR, back 4ER to the b wire. When AK is released and Rl shortcircuited, 4ER operates and removes the tripping shunt from the a and b wires. 4AR shunts condensers C3 and C4 by higher capacity condensers C5 and C6 sufficient to aord proper conversation between the calling and called parties. The current supply for the absentee subscribers transmitter comes from the positive and negative batteries through relays CDR and CER which have relatively high resistances to prevent damage to the transmitter. N

When the calling party hangs up, ground is removed from the c1 wire, 4AR releases and restores the listening circuit to its normal condition. It should be noted that the subscriber has full control of the recorder even while talking and because of this may, if he so desires, permit a recorded message to be listened to by a calling subscriber.

Many modifications are possible. For example, by the use of an additional pair of Wires to the absentee station, it becomes easily possibly to arrange the recorder circuit so that messages may be listened to by, for example, the subscribers secretary while the main line is being used for conversation. With this extra pair of wires, it also becomes possible to connect the recorder at will to the line to record conversationfas well as messages when the subscriber is absent.

What is claimed is:

1. In a telephone exchange system, a plurality of numerically designated subscribers lines,

means including groups of selector switches for establishing a connection between a calling and a called line, a plurality of special line service circuits, means controlled over a line in accordance with a numerical digit for operating means including a selector to select a circuit, a iirst relay associated with each circuit and operable to establish a connection between said line and the selected circuit, a second relay controllable over said line, a locking circuit for the iirst relayv controlled in a back contact of the second relay, and means in said selector for applying a signal to said line and for releasing the selector and other means employed in the selection of the circuit.

2. The telephone exchange system according to claim l, and in which the first relay has contacts connected with said line over a condenser and the second relay.

43. In a telephone exchange system, a plurality of numerically designated two wire subscribers lines, means including groups of numerical selector switches for establishing a connection between a calling and a called `line, a plurality of special line service circuits, means controlled by a line in accordance with numerical digits for operating some of said selectors to select a circuit for the line, a first relay for each circuit energized upon its selection and having contacts connected with its circuit and with the two wires lof said line, a second relay connected with said line and controllable thereover, a locking circuit for the rst relay controlled in a contact of the second relay, means for applying a signal to said line, and means for releasing the selectors and other means used in the selection of the circuit. Y 4. 'I'he telephone system according to claim `3, and in which the second relay has two differentially wound windings, one connected in series in each line wire of said line and with the selected circuit over the contacts of the iirst relay.`

5. In a telephone exchange system, a plurality of numerically designated two wire subscribers lines, means including groups of numerical selector switches for establishing a connection between the two wires of a calling and a called line, a plurality of special line service circuits, means controlled over the two lwires of a line in accordance with numerical digits for operating some of said selectors to select one of said circuits, a first relay for each circuit energized upon its selection and having contacts connected with its circuit and With the two wires of said line, a second relay having a winding in each Wire of said line, a locking circuit for the rst relay controlled in a contact of the second relay, and means for releasing the selectors operated in the selection of the circuit.

6. The telephone system according to claim 5,

and in which the line Wires of said line extend over the windings of the second relay to a group of selectors, a branch connection from contacts of the first relay to the wires'of said line between the windings of the second relay and the subscribers station, and condensers in said branch connections.

'7. In a telephone exchange system, a plurality of subscribers lines,fmeans including groups of numerical and non-numerical switches for establishing a connection between a calling and a called line, a plurality of special'line Vservice selection circuits accessible over a selector under the control of a line, a rst relay in each of said selection circuits energized upon the selection of the circuit by said selector, a plurality of special line service circuits, a second relay responsive to the energization of the first relay for connecting one .of said service circuits with said line, a third relay controlled over said line, a locking circuit for the second relay controlled in a back contact of the third relay, a signal in said selector applied to said line upon the selection of a service circuit, and means also operable upon the selection of a service circuit for releasing the selector connecting the line with the selection circuit.

8. In a telephone exchange system, a plurality of subscribers lines, means including groups of numerical and non-numerical switches for establishing a connection between a calling and a called line, a plurality-of special line service selection circuits accessible over a selector under the control of a line, a iirst relay in each of said selection circuits energized upon the selection of the circuit by said selector,h a plurality of special line service circuits, a second relay responsive to the energization of the rst relay for connecting one of said service circuits with said line, a third relay having two differential windings connected in series with said line, a locking circuit for thel second relay controlled in a back contact of the third relay, a signal in said selector applied to said line upon the selection of a service circuit, and means also operable upon the selection' of a service circuit for releasing the selector connecting the line with the selection circuit and all said relays except the second relay.

9. In a telephone exchange system, a plurality of subscribers lines, means including groups of numerical and non-numerical switches for establishing.V a connection. between afcalling rand a called line, a plurality of special: line service sethe selection ofthe circuit, a plurality cf specialline service circuits, a second relay responsive to the energization of the rst relay for connecting one of said service circuits with the'last-mentibned line, al third relay having two differential windings connected in series with said line, a locking circuit for the second relay controlled in a bank contact of the third relay, a fourth relay associated withv the selector which selected the circuit, a fifth relay common toV all the first relays, a circuit for the fourth'rel'ay jointly controlled by the lirst andthe fth relays, a signalV applied to said line under Ythe control of said fourth relay-i and means responsive to the operation ofv said fourthY relay for releasing said some of said selectors connecting said line with the selection'circuit 'and all said relays except the second` relay. y

10. In a telephone exchange system, a plurality of subscribers lines, means including groups of U numerical and non-numerical switches for establishing a connection between a calling .and `a calle'dline,V saidnumerical. switches including groups of first, second and third selectors, each of said selectors having levels of terminals and brushes cooperating therewith, a special line service selection circuit multipled to each level of certain third selectors, trunks connecting one l'evel of certain second selectors to the brushes of said certain. third selectors, trunks connecting one level ofthe first selectors tothe brushes of said certain second selectors, a first relay in each of said selection circuits energized upon the se.-

lection of the circuit by one of said certain third.,

selectors, a plurality of special line service circuits, a second relay responsive to the energization of the first relay for connecting one of said service circuits with the calling line, a third relay havingY two. differential windings connected in serieswith said calling line, a locking circuit for the second relay controlled inf a back contact of the third relay, a fourth relay associated with.`

each of said certainthird selectors, a fifth relay common to all the first relays, a circuit for the fourth relay jointly controlled by the first and the fth relays, a signal applied to said calling line under the control. of said fourth relay, and means responsive tothe operation of said fourth relay for releasing the. selectors connecting the calling line with the selection circuit and all said relays except the second. relay.

l1. In a telephone exchange system, aplurality of' numerically designated two-wire subscribers lines, means including groups of numerical selector switches-for esta-blishing a connection between thetwo wires of a'calling and a called line, a plurality of specialv line service circuits, means controlled over the two wires of a line in accordance with numerical digits for operating some of' said selectors to select one of said circuits, a rs't'relay for each circuit operated upon its selection and having contacts` in series in each wire of said line and contacts connected with the associated service circuit, a second relay having a winding connected in a line wireA between the subscribers station and. the contacts of the rst relay,v and a circuit for the first relay controlled in a contact of the second relay.

12; In a telephonefexchange system, a plurality of numerically designatedv two-wire subscribers? lines, means including groups of numerical selector switches for vestablishing a connection lbetween the two wires of a calling and a 'called line, a plurality of' special line service circuits, means controlled over the two wires ofV a line in accordance with numerical digits for operating some of said selectors to select one of said circuits, a first relay for each circuit energized upon its selection and having an armature and a back contact in series in each wire'of said line and front contacts connected'with the associated 'service circuit, a second relay having two dinerentially wound windings, one connected in series in each line wire between the subscribers station and the armatures of the first relay, a lockingicircuit for the rst relay controlled in a backcoutact of the second relay. u 'Y 13. In a telephone exchange system, a plurality of numerically designated two-wireV subscribers lines, means including intermediate and iinal selector switches for establishing alconnection between the two wires of a calling and a called line, the final selectors having sets of terminals in which extensions of the two wires and of test and control wires of each line terminate, a plurality of special line service positions, means con-- trolled over the two wires of a line in accordance with numerical digits forqoperating. a selector to select one of said positions, a firstrelay for each position energized over the test ,wire extension of said line and having contacts in each linewire of said line and extensions thereof, a second relay having a winding in a line .wire between the subscribers station and the contacts of the iir'st*y relay, a locking circuit for the rstrelay. controlled in a back contact of the second relay, and paths leading to the selected position over said contacts of the first relay.

14. In a telephone exchange system, a plurality of numerically designated two-wire subscribers lines, means includingV intermediate andnal selector switches for establishing a connection between the two wires of a calling anda called line, the final selectors'having sets of terminals in which extension of the two wires as Well as of test and control wires of the lines. terminate, a plurality of special line service positions, means controlled over the two wires of a line in accord.- ance with numerical digits for operating an intermediate selector to select one of said positions, a rst relay for each position energized over the test wire extension of said line and having arman tures, one inserted in each line Vwire of said line and cooperating back and front contacts, the line wire extensions to terminals of said line in the nal selectorsbeing connected to back contacts cooperating with the armatures inserted in the line wires, and to two other armatures of the first relay, a second relay having two dilferentially wound windings, one connected in series in each line wire between the subscribers station and the4 armatures of the rst relay inserted' in the line wires, a locking circuit for the rst relay controlled in a back Contact of the second relay, and paths leading to the selected position over` the armatures and cooperating front contacts of the.

first relay. 15. In a telephone exchange system, a plurality of numerically designated two-wire subscribers lines, meanssincluding intermediate and nallV selector switches for establishing av connection be.-Y

tween the two wires of` a calling anda called line.

said final selectors having sets" of' terminals in.

which extensions? of the two line Wires, as well tor to select one of said circuits, a iirst relay forV each circuitenergized over the test wire of said linevand having contacts in each wire of said line,v a second relay having a winding in one line wire between thesubscribers station and the Acontacts of thefirsturelay, a locking circuit for the irst` relay includinga back contact of the second relay, a third relay controlling the signal, a fourth and a fifth relay associated with said position and controlling the circuit of the third relay, a

circuit for thejfourth relay including the control wire extension of said line and a contact of the fifth relay,` paths from thel line Wire extensions terminating in the nal selectors over. front contacts cf the 4first relay toV contacts ofthe fourth relay, anfenergizing circuit for the iifth Vrelay including front contacts o f the rst relayand the rsub-,station of said line, contacts for thevfth relay, connecting the jack with the two wires of sajdline over front contacts of the rst relay, and ,a relaymat the position for applying ringing current to saidline controlled by said ring-back -I s i. v16,.InV avtelephone exchangesystern, a plurality lof Inumerically designated `two-wire subscribersA lines, a Sub-station foreach line, a key at some of thersub-stations for grounding oneof, theline wires, means including intermediate and final selector switches for establishing a connectionibetweenthe two ,Wires of acalling and a called line, said nal selectors having sets of terminals in which extensions ,of` the two line wires, aszwellas a test and a control wire of each line terminate,a plurality of special line servicercircuitsan voperators position at each circuit, each Position` comprising a jack, a signal, and a plurality of cord circuits, a listening and a ring-back keyineach, cord circuit, meanscontrolled over the ,two wires of a line in accordance with numerical digits forA operating `an intermediate selector ,.to select one of said circuits, a double wound iirst relay for each circuit energized over onewinding and the test wire of said line,` and having ank armature in, each yline wire Yand in each line wire extension of saidline, back contacts for said relay,v connecting the extensions of the line wiresy of said line with the armatures in the line Wires, a second relay having two diierentially wound windings, lone connected in series in each line wire between the subscribers station and the armatures in the line wires, a. locking circuit for the rst relay including its second winding and a backcontact of the second relay, a third relay bridged across the two V,conductors at the jack over 'a condenser, a circuit for.` the signal controlled bythe third relay, a fourth andv a fth relay .associated with said position andy controlling the circuitof the third relay, a circuit for the fourth relayincludingv the control wire of .said line and a contact of the fifth relay, paths extending from the line wire extensions terminating inthe nal selectors over `front .contactsoi the` yiirst relay to'frontand back contacts of thefourth're1ay,:to the. latter overcondensers, an energizinglcir'cuit yfor the fth relay including frontcontacts offthe irstrelay and the iirst rer layarmatures: in the. line wires, contacts ,for the fth relay:connectingA the,y conductors leading to the jack with the line wires over iront contacts of the rst relay, and ,a lrelay-inthe service circuit for applying ringing yci'irrent to said line controlled by said ring-back key; Y .I

17. In a telephone exchangesy'stem, a plurality Yof numerically designated lines, means including automatic selector switches operable in accordance with the numerical designations of lines for interconnecting vcalling and called lines, a plurality of` phonograph devices at the exchange, eachv of saidV devices having means for recording and for reproducing speech, a first connection established from a line over some ofesaidselector switches under the control of said line to take into use an idle device, means operative thereupon for establishing a' second cone nection from the device taken into use to said' line and releasing the rst connection, means operable over said line for operating thel phonograph device taken into use to reproduce speech' recorded thereon over thesecond connection, means operable overa third connection established with said'line through said automatic selector switches for connecting the-phonograph device taken into use with the third connection, andmeans operative thereupon Aforactuating the deviceto record speech transmitted over the third connection. "l i 18. In a telephone exchange system, a' plurality of numerically designated lines, means, including intermediate andfinal selector" switches operable in'accord'ance with the numerical designations of lines -or intercon'r'ie'cting` calling and called lines, a, plurality of phonograph devices at the ei'irchanvgeacho saidmdevice's having means for recording and for reproducing speech, a first connectionV'establishe-d from aline overan intermediate selector under the control of said line to take into use'an idlewx'ievize` relay' means operative thereupon for Vestablishing a second connection tothe device taken into use lfrom said line and releasing tlfie;I rst'connection, means operable oversaid line and including said intermediate selector to select the phonograph device taken Vinto use and `for operating it to reproduce speech recorded thereon over said second connection, a third connection established with the de,- vicet'aken into use over a nal selector operated in accordancek with the numbery of said line, means operableV lthereupon for actuating the phonograph' device taken into use to record speech transmitted over the.third connection, and signal means controlled by the phonograph device connected withv said lineover the second connection.' i 19. Thetelephone. system according to claim 18, and iniwhich the phonographv devicehas a normal and a plurality of operating positions, and means controlled by said line over the second connection for moving the device into any one Yotsald' positions@ l 20. The tele-phone systemac'cording to Vclaim 18,` and in'which the'phonograph device has a normal anda plurality of operating positions, and acircuit fortheisignal means closed only in the normal-position oi the device. 2 1.. r,'Ille telephone system according to claim 18, and in which the phonograph ldevice has aV normal and` a plurality of `operating positions, and a circuit for the signalmeans closed upon the selection of 4the QdvicevbyV the intermediate selector.

.22, Inv a telephone exchangeQsyst/em, a pluaccordance' with the numericaliv designations cf lines for' establishinga talking. connection Y'between calling and called lines-, l aplurality of' i Vphonograph c devices 'at the exchange, eachc said; devices having means for-recording and for reproducingspeech and meansfor moving it from a normal towards an actuated position and back intol normal', a rst. connection established,` from; aline over some of'said selector switches under the control of' said line to take into. use an idle device,l relay means operative thereupon for r establishing a secondv connection to the. device taken into use from said lline `and releasing the first connection', means operableV over said line and, including some of said' selectorswitchesto select the phonograph device takeninto -use to reproduce speech recorded thereon, means operable over 'a talking' connection establishedL withsaid line for actuating the phonograph device taken into use to record speech,A and means-tor signaling to said line Yover the second 'connection the position of'the phonograph device takenv into use. f f

23. Inja telephone exchange system, a. pluralityof numerically designated, lines', means including automatic selector switches operable in accordance with the numerical designations of' lines for interconnecting callingY and called lines,

aplurality of phonographdevces at the exchange, each of said devices'jhaving means for recording 'and for` reproducingv speech,` common Vreproducespeech recorded thereon, and means operable over a connection established with said line through sai-d' automatic selectorf switches" to asse-,eco

nation of lines 'fory interconnecting calling and called` lines, a plurality of.- phonograph devicesY at the exch-ange, each or* lsa-idvdevices having: speech recording and reproducing means, corn.l mon control means Ifor all the phonograph-de#- vices includingan amplifying tube; a first conneet-ion established' from a line over an internas-- diatek selector underthe control 'of said: line to take into use an'idledevice, means operative l thereupon forl establishing a secondconnectionfrom said line'to; the device taken into use and for releasing the first'. connection, means controlledover saidvli-ne to operate anintermediate selectortoselectthe devicetaken intouse, means1 operative thereupon to connectY saidl recording and reproducing means; over saidE tube with the second connection, a third' connection established with the device over a finalselector, and'i means operative thereupontoextend the connec tion over said` tube withsaid means for recording and reproducing speech. 'Y

26; In a telephoneexchange sys-tem, a plurality of numerically designated-lines, means including intermediate and final selector switches, operable in accordance` with the numerical designations of lines for interconnecting cal-lingandi called lines, -a plurality ot phonograph devicesl at the exchange, each of said devices having speech underl the control ofv said line-v totake into use an idle device, relay means operative-thereupon for establishingy a secondi connection lfrom said lineto the device taken into use andA for release ing the lrst; connection, means. controlled over connect the common control; with the phonoy graphv device taken into usefor operating; itto recordspeech,

'211i In a telephone exchange system, a plural-v ity" oit-'numerically designated lines, means includingv intermediate and iina'l` selector switches operable in accordance Vv vith the numerical des'- i'gnations oflines for interconnecting "calling and called-lines, a plurality ofY phonograph devicesV at the exchange,` eachV of' said devices having means for recording and' for reproducing; speech, common control means for al1 the phonograph devices, a4 rst connection, established fromi a `line over' an intermediate selectorv under the control ofv said line to take'into use an idle device, relay meansoperative thereupon forestablishing a second connection to the device taken into use from said line and releasing the rst connection, means` controlledl over said line to operate an intermediate selector to select the device taken into usepmeansoperative thereupon to connect the common control' with thephonograph'devi'ce taken into use andv for' operatingV the device to reproduce speech recorded thereon, a third connection establishedewith said device overY a final selector and means operative thereupon to c onneet thecommon control` with said device `and for operating it to record` speech: f

25. In a telephone exchange system, al plural'- ity ofnumerically' designatedli-,nes means including intermediate vand V:final selector switches operablein accordance With-the'numericall desigreproducing speech.

said line to. operate an intermediate selector-to select the device take-ni into use, means operative 'thereupon` to. couple said recording andY repro-V dueing means. with the-grid `of said tube and' to coupleE the` anode: of said tube with- -the Vsecond connection, a third connectionv established with the `device overa final selector and means opera` tivethereupon` to couple the 'grid of' lsaid tu-be V with the third' connection and to. couple the` anodev of' said tube with said` means for recording and 27. Ina. telephone exch-ange systennaplural` ity of numerically designated lines,l :means-.fine chiding intermediate and nal 'selector' switches, operable in accordance withthe.numeri'ca11.d'esig-r=4 nations of lines for interconnecting .calling and called lines, a plurality of vphonograph devicesat the exchange, eac-h off-saiddeviceshaving speech recording and reproducing means, comnwn-.cona trol means for all'. the phonograph devices includ. ing anaxnplifying tube having anode, .cathode and grid electrodes, afirst..connectionrestablished from aline overfan. lintermediate selcctorfunder the control of saidV line Atovtakefirnio. use an idle device, relay means ope-:rative thereupon; for: .es-.a tablishing a second connection trOmzsaid tothe device 'taken into. use and for releasingsaid means for recording and reproducingfspeech, a'voiceV operated relay in the anodecircuit, a time operated devicecontrolled by the last-mentionedy relay, and'means for advancing the phonograph device controlled'by theftime operateddevice. Y' 28. In a telephone exchange system,-l a plurality of numerically designated lines, means including intermediate and nal selector switches, operable "in accordance with the numerical 'designations of' lines forinterconnecting calling and called lines, a plurality of vphonograph devices at `the exchange, each of *said devices having speech recordingjand'reproducing means and a record erasing means, common control means-for all the' phonograph devices vincluding an amplifying tube having anode, cathode and grid electrodes, a first connection established from a line over: an I'intermediate selectorI under-the control of said Aline to take into use an idle device, relay means operative thereupon for establishing a second lconnection from said line to the device taken intouse and for releasing the rs't connection, means controlled over said line to operate an intermediate selector to `select thefdevice taken into use, means operative thereupon to couple said recording and; reproducing means with thev grid of saidtube and-*to couple-the anode of said tube with the `second connection, a-third connection established with the'device -overa nal selectonand* means operative thereupon tooperat'e therecord-erasing meansL and to couple the grid of said tube with the third .connection and to couple vthe anode of said. tube with said means for recording and reproducingy speech. `v29: The systemffaccording-to claim 24,*l and means in said commoncontrol meansv and controlled over said line Tand the second connection for advancing' saidi phonograph device into any position. C. V30. The system laccording to.: claim 24, and in which the phonograph devicev has a normal and operated position, and meansz in-said common 'control and controlled over'said line and the second connection-for moving said phonograph device into the normal or any operated position.

31. In a telephone exchange system, .aplurality of numericallydesignated lines, means including automatic selectorV switches'` operable inA accordance. with the numerical designations of lines for interconnecting lcalling andcalled'lines,

a plurality of phonograph devices at;r the exchange, .each-of, said-,devices having, means for recording and ior reproducing speech and means formoving it'from'fa normal towards an actuated position and back into normal, a rst connection established from a line to take into use an idle device, said iirst connection including one of said selector switches operated under the control of said line in accordance with a numerical digit, relay means operative thereupon for establishing a second connection from said line to the device taken into use, means operable upon the establishment of the second connection for releasing said iirst connection, means operable over said line and including said selector switch operated in accordance with another numerical digit to establish a third connection to the phonograph device taken into use to reproduce speech recorded thereon, means operable over a connection established with said line through said automatic selector switches in' accordance with the numerical designation of said i line for actuating the phonograph device taken into use to record speech, and means controlled over said line and the second connection for signaling to said line over said second connection the position of the phonograph device taken into use. f l

` 32. In av telephone exchangel system, a plurality of numerically designated lines, means including intermediate and final selector switches operable in accordance with the numerical designations of lines for interconnecting calling and called lines, a plurality of phonograph devices at lthe eX- change, each of said devices having means for recording and for reproducing speech and means for moving it from a normal towards an actuatedl position and back into normal, a first connection established from a line to take into use an idle device, said first connection including an intermediate selector operated under the control of said'line in accordance With a numerical digit, relaymeans operative thereupon for establishing a second connection from said line to the device taken into use, means operable upon the establishment of the second connection for releasing said lirst connection, means operable over said line and including said intermediate selector operated in accordance with another numerical digit to establish a third connection to the phonograph device taken into use, meansv operative thereupon for connecting the phonograph device with the second connection and actuating it to reproduce speech recorded thereon, a third connection established with said device through a final selector operated in accordance with the numerical designation of said line, means operative thereupon for actuating the phonograph device taken into use to record speech transmitted over the third connection, and means controlledover said'line and the second' connection-'for signaling to said line over said connection the position of the phonograph device taken into use.

33. In a telephone exchange system, a plurality of lnumerically designated lines, means including rautomatic selector switches operable 'in accordance with the numerical designations of lines for interconnecting calling and called lines, a plurality of phonograph devices at the exchange, each of said devicesy having means for recording and for reproducing speech and means for moving it from a normal towards an actuated position and back into normal, common control means for all said phonograph devices includingY an amplier and a source of current supply, a iirst connection vestablished from a line to take into use anidle device, said rst connection including one of said selector switches operated under the control of said line in accordance with a numerical digit, relay means operative thereupon for establishing a second connection from said line to the device taken into use, means operable upon the establishment of the second connection for releasing said rst connection, means operable over said line and including said selector operated in accordance with another numericalo line over said second connection the, position` of thefphonograph deviceftaken into use.

34. In a telephone exchange system, a plurali-'tif-l olfnurnericallydesigrflated` linesfmeans including( -alrtzlatic selector switches; operable. in accord rice with the numerical designations of linesior interechnectiragy calling and4 called 1ines,. a, plurality or phonograph devices at the exchange, each ofsaid devices hav-ing mea-ns for recording and for reproducingspeech and means for mov'- it, from a normal-towardsan actuated positiony and back. into normal,y common control mea-ns for all said: phonograph devices including, @mi amlzlierg, a. sourcel of current supply and a phonograph' records, a rst connection establisllcdrfrom line to take. into use an idle device, .said `first. connection including one of said selector .switches operated under the con-trol or saidline in accordance; with a -numerical digit-p relaxt? meal-1S.- operatiyej 'thereupon'. for establishing a second connect-ion vfrom said line yto theA device taken into use. means operable upon the estalo- Nehmen-tf. oI the secondv connection for releasing said connect-ion, means operable over. said line and including saidaselector Vswitch operated in .accordance with another numerical digit to. establish a third connection to thev phonograph .dei/ice taken into .use and to connect. the commom .control therewith for reproducing speech liecordedl thereon and transmittingY it through accesos In the. system according to, claim 35,5, .a numerical-lr operable device lassociated wlthleacn linefor controlling-fthe automatic .Switches the system according 1z0/claim 35.. a switclr associatedwith each line,- forV controlling theswitchinemeans., v

In atclephone exc,lectricefexistentel plurality @numerically designated, lines,l means7 including; numerical voper-.ated.aprison-ratio switches for. cona, .callingmitha called.L lin-e,y means.. irl--4 cludine. an identification circuit for identifying. thenumcrical desig,nationv or the calling line. pluralityl ci Vspecial s errice.` equipments at the exe challseaswii hing. means. operable to connectfone. of. saidelmi ments a line.,J means. including. some of' said automatic. switches and. said identiiicction i for: oper-.atingJ said .snzszitchingg.v means operable thereupon for restore ina `to normal the automatie1switche-s andidemy tiocation .circuit- Y 3.a. system. according tof claim 3.8,. a operable device-associated with each line rer. controlling said automatic. switchesY to connect with; said identication circuit,A

said; amplifierinto said third. connection, means v y operable: over a fourth connectionr established With Said line through said automatic selector .Switches in; accordance with thev numerical desig.-

nation. .0.f .said line connecting the phonograph record. in the common control with Vthe fourth connection. and for connecting the common control With the phonograph device taken into use toX record speech thereon which -is transmitted from. the fourth connection over said amplifier, and-means controlled over said line and the second connection for signaling to said line .over

said second connection the position of the phono-L 4&2'.` In` the syst m according; to. claim 38.,. means .associated th; cach. lisce for.` controlliua the-.operationorsaidswitclrinameans.

ci; rn. a. telephone. rohen-ee erstem, a plural-ltr or numerically-.designatedlines, .means includlia numerically operated autocratic switches; tor.-

kconnecting a. calling; with a; called. line., means.. inr

cluding an -identicatilon circuit for; detlfllg; the numericar .designation of the .call-ius; line.. means associated with each; lille: .fillcQlzflQlilflg; said switches, a plurality of; speciali Service equipments. at; theexchanse.. a rel-ar for, eachv equip-- mentoperahlevto, connectit: with. a, line. means; responsive -tocertain operation. vof one of; said switches to actuate said identication circuit and relay;` and means operable thereupon 4for restoringl to normal. *the4 automatic SWitQhcS. aridi identification circuit; Y

42:11u the. system according to claim. 4l, a second relay for' each line controllable. thellOS/el and controlling the. operation. ci .the mst-mene t-ro'rred relay; l 43.1@ the; system according to.: claim. 41 a; differentially wound; relay for .each line, with ii-tS. windings; connectedv in series in .the line, a. locking .circuit` for the; lrrrst--merrtioned relays controlledby'the difierentially wound relays; and a grounding kerV associatcdwith each line.

GERALD. DEAKIN.. 

